Currently, there are two types of cameras in use in reactor vessel work, namely black and white cameras and color cameras. Black and white cameras are generally based on tube technology, are radiation resistant, and are typically in the shape of a one foot long, one inch diameter tube. Because an operator cannot get into a reactor vessel once the plant is operational, remotely positioned cameras must be used to perform inspections inside the reactor vessels. Directing these black and white cameras in the reactor vessel is generally performed by twisting and adjusting a rope tied to the head of the camera and the camera cable that comes out of the back end of the cylindrical camera tube. Because the camera is not held by anything rigid, camera positioning is easily affected by any flow in the water in the area. Rotating the camera by twisting the rope and the cable is extremely difficult since there can be an excess of 60 feet between the operator and the camera. Moreover, if there is too much twist in the rope or the cable, the camera can swing by the desired target. Because the only balancing force is the resistance of the water around the camera, rotational adjustments of the camera's position must be made slowly. In addition, it can take a great deal of time to return the camera to the desired target if the camera swings by the target. Although motorized tool heads may assist in the positioning of the camera, these tool heads tend to greatly increase the camera package size and therefore cannot be used where space is a consideration, such as in restricted access areas in nuclear reactors.
Color cameras are typically solid state CCD technology-based and are not radiation resistant, which prevents their use in certain areas of a nuclear reactor, e.g., where access is difficult. Color cameras are usually controlled by installing them on remotely controlled positioner arms. The larger dimensions of a color camera in the positioner is less of a hindrance for most applications where the color camera can be used. However, for tasks where access is restricted and radiation dose rates do not prevent use of a color camera, a manual positioner could be used.
One such conventional manual camera positioning device is depicted in FIG. 1. In the camera positioning device 30 shown in FIG. 1, a camera holding fixture 32 is connected to a rigid handling pole 33. The camera holding fixture 32 has a first portion 34 integrally connected to a second portion 35 such that the camera holding fixture is generally in the shape of an “L”. A camera 36 can be rotatably affixed to the second portion 35 so that the camera 36 is positioned to one side of the handling pole 33. A weight 38 may be added to the cable exit end of the camera 36 to raise the opposite end of the camera 36 (e.g., the lens end) when the cable 37 is slack. The camera 36 can be positioned by pulling and releasing the camera cable 37 that exits from the rear of the camera 36. Although this manual camera holding device is easy to operate, it has numerous disadvantages. For example, the camera holder 32 limits the ability of the camera 36 to be pointed upward. In addition, the weight 38 provides a counter force to pulling on the camera cable 37, which increases the weight that must be supported by the operator and increases the overall size of the camera positioner. Further, by positioning the camera 36 to the side of the handling pole 33, the camera positioning device 30 has a significant width, which can prevent its use in narrow locations.
It is therefore desirable to provide a camera positioning device that can easily and effectively stabilize a camera in a remote location that overcomes the disadvantages of the known conventional camera positioning devices.